<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>表单案例</title>
    <link href="../css/register.css" rel="stylesheet">
</head>
<body>
<div class="form-div">
    <div class="reg-content">
        <h1>欢迎注册</h1>
        <span>已有帐号？</span> <a href="#">登录</a>
    </div>
    <form id="reg-form" action="#" method="get">
        <table>
            <tr>
                <td>用户名</td>
                <td class="inputs">
                    <input name="username" type="text" id="username">
                    <br>
                    <span id="username_err" class="err_msg" style="display: none">用户名不太受欢迎</span>
                </td>
            </tr>

            <tr>
                <td>密码</td>
                <td class="inputs">
                    <input name="password" type="password" id="password">
                    <br>
                    <span id="password_err" class="err_msg" style="display: none">密码格式有误</span>
                </td>
            </tr>

            <tr>
                <td>手机号</td>
                <td class="inputs"><input name="tel" type="text" id="tel">
                    <br>
                    <span id="tel_err" class="err_msg" style="display: none">手机号格式有误</span>
                </td>
            </tr>
        </table>
        <div class="buttons">
            <input value="注     册" type="submit" id="reg_btn">
        </div>
        <br class="clear">
    </form>

</div>


<script>
    // var usernameInput = document.getElementById("username");
    //
    // //1.2 绑定onblur事件 失去焦点
    // usernameInput.onblur = checkUsername;
    //
    // function checkUsername() {
    //     //1.3 获取用户输入的用户名
    //     var username = usernameInput.value.trim();
    //
    //     //1.4 判断用户名是否符合规则：长度 6~12
    //     var flag = username.length >= 6 && username.length <= 12;
    //     if (flag) {
    //         //符合规则
    //         document.getElementById("username_err").style.display = 'none';
    //     } else {
    //         //不合符规则
    //         document.getElementById("username_err").style.display = '';
    //     }
    //     return flag;
    // }

    var usernameInput = document.querySelector('#username');
    usernameInput.onblur=checkUsername;
        function checkUsername(){
    var username = usernameInput.value.trim();
           var flag= username.length >= 6 && username.length <= 12;
    //1.4 判断用户名是否符合规则：长度 6~12
    if (flag) {
        //符合规则
        document.getElementById("username_err").style.display = 'none';
    } else {
        //不合符规则
        document.getElementById("username_err").style.display = '';
    }
    return flag;
}

    var passwordInput = document.querySelector('#password');
    passwordInput.onblur =checkPassword;
    function checkPassword(){
        var password = passwordInput.value.trim();
        var flag= password.length >= 6 && password.length <= 12
        //1.4 判断用户名是否符合规则：长度 6~12
        if (flag) {
            //符合规则
            document.getElementById("password_err").style.display = 'none';
        } else {
            //不合符规则
            document.getElementById("password_err").style.display = '';
        }
        return flag;
    }
    var telInput = document.querySelector('#tel');
    telInput.onblur =checkTel;
        function checkTel(){
            const tel = telInput.value.trim();
            var flag = tel.length == 11
        //1.4 判断用户名是否符合规则：长度 6~12
        if (flag) {
            //符合规则
            document.getElementById("tel_err").style.display = 'none';
        } else {
            //不合符规则
            document.getElementById("tel_err").style.display = '';
        }
        return flag;
    }
    var regForm = document.querySelector('#reg-form');
        regForm.onsubmit= function (){
            var flag=checkPassword()&&checkUsername()&&checkTel();
            return flag;
        }
</script>
</body>
</html>